Technical Field
The subject matter described herein relates to internal combustion engines, and to exhaust gas recirculation systems and methods.
Discussion of Art
Engines include a plurality of cylinders having combustion chambers with pistons disposed in the combustion chambers. Intake air is directed into the combustion chambers and is compressed in the combustion chambers. The ignited fuel generates pressure in the combustion chamber that moves the piston. The ignition of the fuel creates a gaseous exhaust in the combustion chamber. Some engines attempt to change the composition of the intake air by recirculating parts of the exhaust gas back into the intake. Exhaust gas recirculation may be referred to as “EGR”.
In a certain configuration, an EGR engine recirculates the gaseous exhaust from one or more dedicated cylinders back into air the intake stream. A cylinder that provides the gaseous exhaust may be referred to as a spender, donor or donating cylinder.
It may sometimes be desirable to have an engine system that has components, features or functions that differ from those EGR engines that are currently available. Likewise, it may be desirable to have engine systems that having modes of operation that differ from those operational modes available on current EGR engines.